Commercial waste, industrial waste, domestic waste, etc., e.g. (hard) plastics, textiles, composites, rubber or waste wood (such as pallets and chipboard), require shredding prior to their final disposal or especially prior to returning them into the recovered substance cycle. Prior art knows single- or multiple-shaft shredders which are loaded, for example, by wheeled loaders, forklifts, conveyors, or manually via a hopper for material feed.
A central element of a conventional shredder is a rotor assembly comprising a rotor being fitted with tear hooks or blades, e.g. with concave milled round cutting crowns. The blades are fixed, for example, by being bolted onto blade carriers, that can be welded into blade recesses or e.g. bolted on, which are machined into the rotor. Shredding the fed material occurs between the blades rotating with the rotor and stationary, i.e. non-rotating counter-blades (stator blades, scraper combs).
The fed material can be pushed in the direction of the rotating rotor, for example, by a pusher element controlled by load-sensing. After being shredded between the rotating blades and the counter blades, the material is discharged through a screen device, which determines the shredding factor according to the screen size, and is conveyed on by a conveyor belt, a screw conveyor, a chain conveyor or an extractor system etc.
Drawer pushers are known in prior art, in particular for a scrap wood shredding machine, which are installed as being mounted on guides. However, these guides foul during the shredding operation, whereby a perfect shredding operation can be disrupted. In addition, the drawer pusher increases the space required by the shredding device. In alternative designs, the pusher element is integrated pivotally entirely or not entirely into the feed and shredding chamber of the shredding device.
Regardless of the design, service activities are in a shredding device to be performed within the machine. Typical service activities include changing the shredding blades at the rotor and cleaning the machine interior space. Access to the machine interior space for extensive cleaning is in prior art possible only after time-consuming disassembly of machine components, such as hydraulic cylinders that move a pusher element or a service hatch. FIG. 1 shows an example of a sectional view through a shredding device 1 known in prior art with a pusher element 2 which with a pivoting motion moves the material to be shredded towards the rotor 3. The shredding device 1 comprises a service hatch 4 in the interior space. In the open state of the service hatch 4, a service person 5 while standing on the floor of the interior space 6 is enabled to perform servicing at the rotor 3, for example, a blade change. The service hatch 4 is hinged at one end to a pivot axle 7 and can be opened by being pivoted about the pivot axle 7. When closed, the service hatch 4 is part of a pusher wall 8 along which the pusher element 2 comprising a pivot arm 2a and a pusher surface 2b performs its pivotal motion. The disadvantage of this design is that extensive cleaning in the area of the pusher element 2 can be enabled only by elaborate dismantling of individual components, such as hydraulic cylinders (not shown) that move the pusher element 2, or hydraulic cylinders 9 that move the service hatch 4.
In view of the above problems, it is therefore an object of the present invention to provide a shredding device in which servicing is facilitated over known prior art by reducing the required disassembly of components.